JPWO2017199550A1 - Proximity sensor, proximity illuminance sensor, electronic device, and proximity sensor calibration method - Google Patents

Abstract

The proximity sensor (100) includes a light emitting unit (101) that emits light, a light receiving unit (102) that generates a measurement current including an object reflected photocurrent and a non-detection target object reflected photocurrent, and an initial measurement current value. And an initial calibration execution unit (120) that updates an offset value corresponding to the non-detection target object reflected photocurrent based on the measured current value when it is equal to or less than the threshold value.

Description

  The present invention relates to a proximity sensor and a proximity illuminance sensor that detect the proximity of a detection object.

  In recent years, mobile devices (electronic devices, more specifically portable electronic devices) having a screen with a touch panel (for example, a liquid crystal screen) represented by mobile phones, smartphones, media players, and the like have been widely used. A mobile device equipped with a proximity sensor that detects (detects) the presence or absence of a nearby object has appeared in the above-described mobile devices that are becoming more multifunctional, smaller, or thinner.

  A conventional proximity sensor and a calibration method thereof will be described with reference to FIGS. FIG. 8 is a diagram for explaining the operating principle of a conventional proximity sensor 900. FIG. 9 is a diagram for explaining the problem of the proximity sensor 900. FIG. 10 is a functional block diagram showing a schematic configuration of the proximity sensor 900. FIG. 11 is a flowchart showing an example of a calibration processing flow of the proximity sensor 900. 9 indicates a pulse signal for causing the light emitting unit 901 to emit light.

  There are various types of the proximity sensor 900 in the past, and a light detection type proximity sensor 900 is often used in small portable terminals such as mobile phones and media players. As shown in FIG. 8, the proximity sensor 900 of the light detection type reflects the emitted light L1 emitted from the light emitting unit 901 in the proximity sensor 900 to the object OB, and the reflected light L2 in the light receiving unit 902 in the proximity sensor 900. By receiving the light, it is determined that the object is close.

  In such a light detection type proximity sensor 900, as shown in FIG. 9 and FIG. 10, it may be used by being incorporated in a housing 960 of a mobile phone 950. In this case, the emitted light L1 emitted from the light emitting unit 901 is reflected by the housing 960, and the light receiving unit 902 may receive the reflected light L3 from the housing 960.

  Here, the reflected light amount of the reflected light L3 due to the reflected light L1 emitted from the light emitting unit 901 being reflected by the housing 960 varies depending on the individual mobile phone and the usage environment. Therefore, when the light receiving unit 902 receives the reflected light L3 from the housing 960, an error in detection distance or a malfunction may occur due to the difference in the amount of reflected light of the reflected light L3 for each individual.

  From such circumstances, there is a strong demand for the realization of a proximity sensor (object detection device) having equivalent characteristics under various mounting conditions. In addition, examples of the index indicating the above characteristics include a detection distance (a distance between the detection target and the proximity sensor when it is determined that the detection target is close) and a malfunction occurrence probability.

  In addition, the following may be considered as a cause that the reflected light amount of the reflected light L3 changes for each individual mobile phone 950 and the usage environment. That is, due to manufacturing at the time of factory shipment of the mobile phone 950, dirt and changes in internal structure due to aging of the mobile terminal 950, the mounting position of the proximity sensor 900 on the mobile phone 950, the housing of the mobile phone 950 after mounting the proximity sensor 900 This is because conditions such as the shape on the body surface (proximity sensor mounting conditions) and the like vary from manufacturer to manufacturer and from model to model. The reason for this is the design aspect of the cellular phone 950 (electronic device) and design restrictions.

  Conventionally, as a countermeasure for preventing malfunction due to reflected light L3 from the casing 960, there is a proximity sensor calibration method, which is described in Patent Document 1, for example.

  An outline of a calibration method similar to the calibration method described in Patent Document 1 will be described with reference to FIGS.

  Specifically, the mobile phone 950 includes a proximity sensor 900, a mobile control unit 951, and a display unit 952. The proximity sensor 900 includes a light emitting unit 901, a light receiving unit 902, an AD conversion unit 903, a storage unit 904, and a sensor control unit 910.

  The light emitting unit 901 is an infrared LED (Light Emitting Diode) that emits infrared light when supplied with current from the sensor control unit 910. The light receiving unit 902 receives infrared light (reflected light L2) emitted from the light emitting unit 901 and reflected by the object OB, and generates a current corresponding to the amount of light received by photoelectric conversion. The generated current is output to the AD conversion unit 903.

  A predetermined threshold value is stored in the storage unit 904 in advance, and the stored threshold value is read by the sensor control unit 910, while the stored threshold value is updated by the sensor control unit 910.

  The AD conversion unit 903 performs AD conversion (analog-digital conversion) on the current output from the light receiving unit 902 and outputs a value represented by a digital signal to the sensor control unit 910.

  The sensor control unit 910 supplies current to the light emitting unit 901 to emit light from the light emitting unit 901 each time incoming / outgoing information indicating a call from the mobile phone 950 or an incoming call to the mobile phone 950 is input from the mobile control unit 951. Let At this time, the sensor control unit 910 generates a new threshold value according to the current value output from the AD conversion unit 903 and updates the threshold value stored in the threshold value storage unit 904. This series of processing is called calibration.

  The sensor control unit 910 that has performed the calibration causes the light emitting unit 901 to emit light, the current value output from the AD conversion unit 903, and the threshold value read from the storage unit 904 (if the threshold value has been updated, the threshold value). The user's proximity is detected based on the comparison result. When the proximity of the user is detected, the sensor control unit 910 outputs detection information to the portable control unit 951.

  That is, the proximity sensor 900 measures the floor noise every time when the mobile phone 950 makes and receives calls, performs calibration, detects the proximity of an object (user), and detects the detection information indicating the proximity of the mobile phone 950. The data is output to the portable control unit 951. When the detection information indicating the proximity of the user is input from the proximity sensor 900, for example, the control unit 951 controls to turn off the function of the touch panel and turn off the display of the display unit 952.

  Next, an example of the calibration processing flow of the proximity sensor 900 will be described with reference to FIG.

  First, the sensor control unit 910 determines whether or not outgoing / incoming information has been acquired from the mobile control unit 951 of the mobile phone 950 (S1001). When the outgoing / incoming information is acquired (YES in S1001), the sensor control unit 910 supplies current to the light emitting unit 901 to emit light (S1002), and a new threshold value is set according to the current value output from the AD conversion unit 903. And the threshold value stored in the storage unit 904 is updated (S1003). S1001 to S1003 indicate a calibration process performed by the proximity sensor 900 when the mobile phone 950 is made, that is, when the proximity sensor 900 is activated. If the outgoing / incoming information has not been acquired (NO in S1001), the outgoing / incoming information is returned to the acquisition determination S1001.

  Next, the sensor control unit 910 supplies current to the light emitting unit 901 to emit light (S1004), compares the current value output from the AD conversion unit 903 with the threshold value read from the storage unit 904, and compares the current value. It is determined whether or not the value is greater than or equal to a threshold value (S1005). If the current value is equal to or greater than the threshold value (YES in S1005), the sensor control unit 910 determines that the proximity of the detection target has been detected (S1006), and outputs detection information to the portable control unit 951. If the current value is less than the threshold value (NO in S1005), the sensor control unit 910 determines that there is no proximity of the detection target (S1007), and ends the process.

  As a result, when the mobile phone 950 is made / received, the proximity sensor 900 is calibrated, for example, due to various external factors in the adjustment process before factory shipment, aging of the internal structure, etc. Even when changes occur, the proximity of the user can be accurately detected.

Japanese Patent Publication “JP 2013-118565 A (published on June 13, 2013)”

  However, the conventional techniques as described above have the following problems. That is, as an example of use of a mobile phone, there is not always a proximity of an object to be detected on the front surface of the mobile phone when making or receiving a call. For example, if a user makes or receives a call while operating a mobile phone, putting it in a pocket or bag, or using a case with a cover, the calibration is performed with the proximity of the detection target. Process. As a result, the threshold value stored in the storage unit 904 becomes large, and even if there is a proximity of the detection target, the proximity cannot be detected, for example, when the touch panel function cannot be turned off, There is a problem that the touch panel reacts and the mobile phone malfunctions.

  The present invention has been made in view of the above problems, and an object of the present invention is to realize a proximity sensor that can accurately detect proximity by performing calibration optimally.

  In order to solve the above-described problem, a proximity sensor according to one embodiment of the present invention includes a light-emitting unit that emits light, and an object that corresponds to the amount of reflected light that is emitted from the light-emitting unit and reflected by the detection target object. A light receiving unit that generates a measurement current including a reflected photocurrent and a non-detection target object reflected photocurrent according to the amount of received light other than the reflected light, and a current value of the measurement current is equal to or less than an initial threshold value And updating the offset value according to the current value of the non-detection target object reflected photocurrent based on the current value of the measurement current, and not updating the offset value when the current value of the measurement current is larger than the initial threshold value. And a first execution unit that executes one calibration.

  In order to solve the above problems, a proximity sensor calibration method according to an aspect of the present invention includes a light emission step of emitting light, and a received light amount of reflected light emitted in the light emission step and reflected by a detection target object. A light receiving step for generating a measurement current including an object reflected photocurrent according to the light intensity and a non-detection target object reflected photocurrent according to the amount of received light other than the reflected light, and the current value of the measurement current is an initial threshold value The offset value according to the current value of the non-detection target object reflected photocurrent is updated based on the current value of the measurement current when the current value of the measurement current is larger than the initial threshold value when And a first execution step of executing a first calibration without updating.

  According to one embodiment of the present invention, it is possible to realize a proximity sensor that can accurately detect proximity by performing calibration optimally.

It is a functional block diagram which shows schematic structure of the proximity sensor which concerns on Embodiment 1 of this invention. It is a figure for demonstrating the principle of operation of the said proximity sensor. It is a flowchart which shows an example of the flow of the process of the initial calibration of the said proximity sensor. It is a flowchart which shows an example of the flow of the process of constant calibration of the said proximity sensor. It is a functional block diagram which shows schematic structure of the proximity illumination sensor which concerns on Embodiment 2 of this invention. It is a perspective view which shows an example of the electronic device which concerns on Embodiment 3 of this invention. It is a rear view which shows the other example of the said electronic device. It is a figure for demonstrating the principle of operation of the conventional proximity sensor. It is a figure for demonstrating the problem of the said proximity sensor. It is a functional block diagram which shows schematic structure of the said proximity sensor. It is a flowchart which shows an example of the flow of a calibration process of the said proximity sensor.

Embodiment 1
Embodiment 1 of the present invention will be described with reference to FIGS. FIG. 1 is a functional block diagram showing a schematic configuration of a proximity sensor 100 according to Embodiment 1 of the present invention. FIG. 2 is a diagram for explaining the operation principle of the proximity sensor 100. 2 indicates a pulse signal for causing the light emitting unit 101 to emit light.

(Configuration of proximity sensor)
As shown in FIGS. 1 and 2, the proximity sensor 100 includes a light emitting unit 101, a light receiving unit 102, a proximity sensor AD conversion unit 103, a storage unit 104, a cover 105, and a proximity sensor control unit 110.

  The light emitting unit 101 emits light. Specifically, the light emitting unit 101 emits light in response to a current supplied from a light emission instruction unit 111 described later. As the light emitting unit 101, for example, an infrared LED that emits infrared light can be used.

  The light receiving unit 102 includes a detection target object reflected photocurrent (hereinafter referred to as an object reflected photocurrent) corresponding to the amount of reflected light emitted from the light emitting unit 101 and reflected by the detection target object (object OB), and the reflection. A measurement current including a non-detection target object reflected photocurrent corresponding to the amount of received light other than light is generated.

  Specifically, for example, the emitted light L1 emitted from the light emitting unit 101 is output to the outside of the proximity sensor 100 as shown in FIG. When the object OB is near the proximity sensor 100, the emitted light L1 is reflected by the object OB. The reflected light L <b> 2 reflected by the object OB enters the proximity sensor 100 and is received by the light receiving unit 102.

  The light receiving unit 102 includes a photodiode or the like, and generates a measurement current by detecting light. The measurement current includes an object reflected photocurrent according to the amount of reflected light L1 emitted from the light emitting unit 101 and reflected by the object OB, and light other than the reflected light L1 (for example, reflected light L3 reflected by the housing 11). The non-detection target object reflected photocurrent according to the amount of received light. The measurement current generated by the light receiving unit 102 is output to the proximity sensor AD conversion unit 103.

  The proximity sensor AD conversion unit 103 performs AD conversion (analog-digital conversion) on the current output from the light receiving unit 102, and outputs a value represented by a digital signal to a measured current value acquisition unit 112 described later. The proximity sensor AD conversion unit 103 is configured by an integration circuit, a comparator circuit, and the like. The proximity sensor AD conversion unit 103 accumulates electric charge flowing in by current, and can convert it into a digital signal by detecting the amount of electric charge. The digital signal converted by the proximity sensor AD conversion unit 103 becomes a digital value correlated with the distance to the detected object OB, and is output to the measured current value acquisition unit 112.

  The storage unit 104 stores an offset value. The offset value is a value corresponding to the current value of the non-detection target object reflected photocurrent. In other words, the offset value is a value used to make the output value from the proximity sensor 100 constant in the absence of the object OB.

  The storage unit 104 stores an initial calibration flag. The initial calibration flag is for recording whether or not the offset value has been updated in the initial calibration. For example, when the offset value is updated in the initial calibration, the flag is set to “1”. If initial calibration is not executed, such as immediately after startup or reset, the flag is set to “0”. In addition, it is desirable that a flag can be set to “0” from the outside when an initial calibration is forcibly performed from the outside due to an abnormal calibration state or the like. It should be noted that there is no problem even if the value of the flag is inverted in each state.

  The cover 105 transmits the emitted light L1 and prevents foreign matter from entering the proximity sensor 100. The cover 105 is made of resin or glass that transmits outgoing light and reflected light.

(Details of proximity sensor control unit)
The proximity sensor control unit 110 always determines whether or not calibration is performed (offset value update) when the proximity sensor is activated and during normal operation.

  When the proximity sensor control unit 110 determines the current state of the proximity sensor 100 and determines that calibration is not necessary, the proximity sensor control unit 110 does not update the offset value. When the proximity sensor control unit 110 does not update the offset value, the proximity sensor control unit 110 subtracts the offset value stored in the storage unit 104 from the digital value input from the proximity sensor AD conversion unit 103. Then, the calculated value is output to the outside of the proximity sensor 100 as a digital value of the proximity detection result.

  When the proximity sensor control unit 110 determines that calibration is necessary, the proximity sensor control unit 110 performs either or both of initial calibration and constant calibration, and updates the offset value. Then, the proximity sensor control unit 110 subtracts the offset value stored in the storage unit 104 from the digital value input from the proximity sensor AD conversion unit 103, and uses the calculated value as the digital value of the proximity detection result. 100 to the outside.

  In the present embodiment, the initial calibration is calibration that is first executed when the proximity sensor 100 is activated, and is for correcting a large error due to floor noise or the like when setting an offset value. In the present embodiment, the constant calibration is a calibration method using an averaging process for correcting the offset value by gradually following a change in the external environment, not following the agility. Is.

  The proximity sensor control unit 110 will be described in detail below. In the following description, in the initial calibration execution determination, the measurement current value acquired by the proximity sensor AD conversion unit 103 is referred to as an initial measurement current value, and the current value acquired by the proximity sensor AD conversion unit 103 is measured otherwise. This is referred to as a current value.

  The proximity sensor control unit 110 comprehensively controls various components in the proximity sensor 100, and includes a processor such as a CPU (Central Processing Unit). The proximity sensor control unit 110 includes a light emission instruction unit 111, a measured current value acquisition unit 112, an initial calibration execution unit 120, and a constant calibration execution unit 130.

  The light emission instruction unit 111 supplies a current to the light emission unit 101 based on instructions from the initial calibration execution unit 120 and the constant calibration execution unit 130.

  The measurement current value acquisition unit 112 acquires the current value output from the proximity sensor AD conversion unit 103 and outputs the current value to the initial calibration execution unit 120 or the constant calibration execution unit 130 as the initial measurement current value or the measurement current value. .

(Initial calibration execution unit)
The initial calibration execution unit 120 (first execution unit) calculates an offset value corresponding to the current value of the non-detection target object reflected photocurrent based on the current value of the measurement current when the current value of the measurement current is equal to or less than the initial threshold value. An initial calibration (first calibration) that does not update the offset value when the current value of the measured current is larger than the initial threshold is executed.

  The initial calibration execution unit 120 includes a flag determination unit 121 (offset value update determination unit) that determines whether or not the offset value has been updated in the initial calibration. The initial calibration execution unit 120 includes a flag determination unit. If it is determined from 121 that the offset value has not been updated in the initial calibration, the offset value is updated in the initial calibration.

  Specifically, the initial calibration execution unit 120 includes a flag determination unit 121 and an offset value calculation unit 122.

  The flag determination unit 121 determines whether or not the offset value has been updated in the initial calibration by determining whether or not the initial calibration flag is “0”. In other words, it is determined whether or not the offset value is updated in the initial calibration.

  The flag determination unit 121 (1) the proximity sensor 100 is activated, (2) a signal indicating that the corrected measurement value is less than or equal to the lower threshold value is received from the lower threshold determination unit 133, and (3) a change in external ambient light is detected. When a signal indicating that this has been received is received from the external light determination unit 134, the initial calibration flag stored in the storage unit 104 is read out. If the flag is “0”, the flag determination unit 121 determines that the offset value has not been updated in the initial calibration. If the flag is “1”, the flag determination unit 121 determines that the offset value has been updated in the initial calibration. Note that the initial calibration flag is “0” immediately after the proximity sensor 100 is activated.

  The flag determination unit 121 transmits a determination result on whether or not the offset value has been updated by the initial calibration to the offset value calculation unit 122.

  When the offset value calculation unit 122 receives a determination result from the flag determination unit 121 that the offset value has not been updated by the initial calibration (the initial calibration flag is “0”), the offset value calculation unit 122 supplies current to the light emitting unit 101. The light emission instructing unit 111 is instructed to do so.

  The offset value calculation unit 122 determines whether or not the initial measurement current value output from the proximity sensor AD conversion unit 103 is equal to or less than the initial threshold value. When it is determined that the initial measurement current value is equal to or less than the initial threshold value, the offset value calculation unit 122 calculates a new offset value based on the initial measurement current value.

  The initial threshold value can be a value including a current value considered to be generated by reflected light L3 (see FIG. 2) due to internal reflection or the like and a proximity detection threshold value used to determine that there is proximity. Specifically, for example, in order to determine that the current value of the non-detection target object reflected photocurrent output from the proximity sensor AD conversion unit 103 by the reflected light L3 is approximately 1000, and the current value of the object reflected photocurrent is close. When the proximity detection threshold value used in the above is 500, the initial threshold value may be set to 1500.

  Here, for example, when the variation in the current value of the non-detection target object reflected photocurrent due to the reflected light L3 of the casing 11 for each mobile phone is large, the offset value cannot be updated in the initial calibration if the initial threshold is small. In this case, the problem can be avoided by setting a larger initial threshold value. Therefore, it is desirable that the initial threshold can be set from the outside.

  The calculation of the new offset value in the initial calibration can be, for example, “new offset value = initial measured current value”, but “initial measured current value−offset value” is the lower limit value of the proximity detection result ( For example, it is desirable to define the calculation of the offset value so as not to be 0). This is because it is possible to determine whether or not the executed initial calibration is an erroneous calibration. The reason will be described below.

  What is output from the proximity sensor 100 as the proximity detection result is “measurement current value−offset value” (corrected measurement value). When only the initial calibration is performed as the calibration, if “new offset value = initial measurement current value” is set in the initial calibration, the initial correction measurement value (initial measurement current value−offset value) “ “0” is output to the outside.

  Here, when the initial measurement current value is obtained in the state where the object OB is present, if the object OB disappears thereafter, the subsequent proximity detection result is degraded. However, if the lower limit value of the proximity detection result is 0, the proximity detection result does not become smaller than 0 even if the object OB disappears. As a result, the proximity detection result is output as “0” which is larger than the actual value, and the distance from the proximity sensor 100 to the object OB calculated based on the proximity detection result becomes shorter than the actual distance, and the proximity determination is performed. It becomes impossible to do accurately.

  In order to avoid this problem, the offset value after the initial calibration is set so that the value obtained by subtracting the offset value from the initial measurement current value (initial correction measurement value) is equal to or greater than the lower limit value (here, 0 or more). . Thereby, it is possible to determine after the initial calibration whether or not the executed initial calibration is an erroneous calibration.

  For example, the initial correction measurement value after the initial calibration is set to 100. If the initial calibration is executed in the absence of the object OB, the corrected measurement value increases when the object OB is moved closer to the proximity sensor 100 thereafter, and the corrected measurement value decreases when the object OB is moved away again. The corrected measurement value never becomes 100 or less.

  However, if the initial calibration is performed in a state where the object OB exists at a position where the initial measurement current value is equal to or less than the initial threshold value, the initial correction measurement value becomes 100, but if the object OB is subsequently removed, the correction measurement value is obtained. Becomes 100 or less. Therefore, by determining whether or not the initial correction measurement value is 100 or less, it is possible to determine whether or not the executed initial calibration is an erroneous calibration. For the above reasons, it is desirable that the new offset value updated by the initial calibration is such that the initial correction measurement value does not become the lower limit value.

  In the present embodiment, the above-described determination for determining whether or not the initial calibration is an erroneous calibration is performed by the lower threshold determination unit 133 at the time of constant calibration described later.

  When the offset value calculation unit 122 calculates a new offset value, the offset value calculation unit 122 updates the offset value stored in the storage unit 104. When the offset value stored in the storage unit 104 is updated, the offset value calculation unit 122 sets the initial calibration flag in the storage unit 104 to “1”, and always performs calibration for a signal that instructs the start of constant calibration. To the corrected measurement value calculation unit 131 of the unit 130.

  When the determination result that the offset value has been updated (the initial calibration flag is not “0”) is input from the flag determination unit 121, the offset value calculation unit 122 does not update the offset value and always performs calibration. Is transmitted to the corrected measurement value calculation unit 131 of the calibration execution unit 130 at all times.

  Further, when the offset value calculation unit 122 determines that the initial measurement current value is larger than the initial threshold value, the offset value calculation unit 122 ends the initial calibration process without updating the offset value, and outputs a signal for instructing the start of constant calibration. It is transmitted to the corrected measurement value calculation unit 131 of the constant calibration execution unit 130. At this time, since the offset value is not updated, the initial calibration flag is not written and “0” is maintained.

  For example, the initial measured current value acquired when the object OB is near the proximity sensor 100 when the mobile phone is activated or when a call is received while operating the touch panel of the mobile phone is calculated as an offset value. Not suitable for. Accordingly, the offset value is updated when the initial measured current value output from the proximity sensor AD conversion unit 103 is equal to or smaller than the initial threshold value, and the offset value is not updated when the initial measured current value is larger than the initial threshold value. Can be used to calculate proximity. In other words, the initial calibration execution unit 120 can appropriately execute calibration in consideration of floor noise, and can accurately detect proximity.

(Continuous calibration execution unit)
The constant calibration execution unit 130 (second execution unit) uses the first offset value, which is the offset value after executing the initial calibration, as the current value of the measurement current generated from the light receiving unit 102 after executing the initial calibration. And constant calibration (second calibration) for updating the first offset value to the averaged value.

  In addition, the continuous calibration execution unit 130, in the continuous calibration, when the corrected measurement value obtained by subtracting the first offset value from the current value of the measurement current generated from the light receiving unit 102 after the initial calibration is always below the threshold value In addition, the first offset value is updated.

  In addition, the continuous calibration execution unit 130 performs the initial calibration and the continuous calibration alternately. In the continuous calibration, when the corrected measurement value is equal to or lower than the lower limit threshold, the first offset value is not updated. Move to initial calibration process.

  Further, in the continuous calibration, the continuous calibration execution unit 130 determines the first offset value when the corrected measurement value is larger than the lower limit threshold and is always equal to or smaller than the threshold and a change in external light is detected. Is not updated, and the first calibration is executed.

  The constant calibration execution unit 130 includes a corrected measurement value calculation unit 131, a constant threshold determination unit 132, a lower threshold determination unit 133, an external light determination unit 134, and an average offset value calculation unit 135.

  When the correction measurement value calculation unit 131 receives a signal for instructing the start of constant calibration from the initial calibration execution unit 120, the correction measurement value calculation unit 131 instructs the light emission instruction unit 111 to supply current to the light emission unit 101. The corrected measurement value calculation unit 131 calculates a correction measurement value based on the measurement current value acquired from the proximity sensor AD conversion unit 103 and the offset value stored in the storage unit 104. Specifically, the corrected measurement value is calculated by subtracting the offset value stored in the storage unit 104 from the measured current value output from the proximity sensor AD conversion unit 103. When the corrected measurement value is calculated, the corrected measurement value calculation unit 131 outputs the corrected measurement value to the threshold determination unit 132 at all times.

  When the corrected measurement value is input from the corrected measurement value calculation unit 131, the constant threshold value determination unit 132 determines whether the corrected measurement value is always equal to or less than the threshold value. The constant threshold value can be a proximity detection threshold value used for determining that there is proximity, for example. The constant threshold is assumed to be larger than a lower limit threshold described later.

  When the corrected measurement value is always larger than the threshold value, it is considered that the object OB is in close proximity. For this reason, the constant threshold value determination unit 132 does not always perform the calibration process, and the constant calibration process ends. When the corrected measurement value is always equal to or less than the threshold value, the constant threshold value determination unit 132 transmits a signal indicating that the correction measurement value is always equal to or less than the threshold value to the lower limit threshold value determination unit 133.

  After the initial calibration is performed, the lower limit threshold determination unit 133 always performs the offset in the calibration when the calculated value (corrected measurement value) obtained by subtracting the offset value stored in the storage unit 104 from the measured current value is equal to or lower than the lower limit threshold. Perform initial calibration without updating values. In other words, when the lower threshold determination unit 133 receives a signal indicating that the corrected measurement value is always equal to or less than the threshold from the constant threshold determination unit 132, the lower threshold determination unit 133 determines whether there is an abnormality in the initial calibration, and the initial calibration is abnormal. If there is, the initial calibration is executed again without always updating the offset value in the calibration.

  When there is an abnormality in the initial calibration, that is, when there is an abnormality in the offset value calculated in the initial calibration and stored in the storage unit 104, the proximity sensor 100 outputs an erroneous corrected measurement value to the outside, As a result, there is a possibility that a mobile phone or the like malfunctions. Therefore, when it is determined that the initial calibration is clearly abnormal, it is necessary to delete the offset value stored in the storage unit 104 and execute the initial calibration again.

  The lower threshold determination unit 133 determines that the initial calibration is abnormal if the corrected measurement value is equal to or lower than the lower threshold. At this time, the lower threshold determination unit 133 sets the initial calibration flag to 0, sets the initial calibration to a state in which the initial calibration is not performed, and then always ends the calibration. As a result, the initial calibration is performed again without updating the offset value in the constant calibration.

  Here, it is desirable that the lower limit threshold value be equal to or less than a value obtained by subtracting the offset value from the initial measurement current value (initial correction measurement value) in the initial calibration. In a state where the initial correction measurement value after the initial calibration is set to 100, for example, from the measured current value generated from the light receiving unit 102 after the initial calibration, it is stored in the storage unit 104 at that time. It is assumed that the value obtained by subtracting the offset value (corrected measurement value) becomes zero. This corresponds to a case where the initial calibration is erroneously executed in the state where the object OB is present, and then the object OB is moved away or removed. Therefore, by setting the lower limit threshold value to be equal to or less than the initial correction measurement value, it is possible to determine that the initial calibration state is abnormal if the correction measurement value is equal to or less than the lower limit threshold value.

  If the corrected measurement value is equal to or lower than the lower limit threshold, the lower limit threshold determination unit 133 sets the initial calibration flag to “0” and sets the state in which the offset value is not updated in the initial calibration. Always end calibration. Thereby, the offset value is not updated in the constant calibration, and the initial calibration is executed again. In addition, the lower threshold determination unit 133 transmits a signal indicating that the corrected measurement value is equal to or lower than the lower threshold to the flag determination unit 121.

  If the corrected measurement value is greater than the lower threshold value, the lower threshold determination unit 133 transmits a signal indicating that the corrected measurement value is greater than the lower threshold value to the external light determination unit 134.

  When the external light determination unit 134 receives a signal indicating that the corrected measurement value is larger than the lower limit threshold value from the lower threshold determination unit 133, whether or not a change in external light (external environmental light) is detected after the initial calibration is performed. Determine whether. When the external light determination unit 134 detects a change in external environmental light, the offset value is not always updated in the calibration, and the initial calibration is executed.

  In the proximity sensor 100 using the light emitting unit 101 that emits infrared light, infrared light such as a white fluorescent lamp and a white LED is used in an environment of a light source containing a lot of infrared light such as sunlight, incandescent lamp, and halogen light. Under the environment of a light source that hardly contains light, the characteristics of light received by the light receiving unit 102 may change greatly.

  Specifically, when the user moves from the outdoor to the indoor, and from the indoor to the outdoor, (1) the proximity sensor 100 is activated in the environment of the light source containing a lot of infrared light, and the light source does not contain the infrared light. (2) When the proximity sensor 100 is activated in the environment of a light source that does not include infrared light and moves in the environment of a light source that includes infrared light, There is a possibility that the proximity sensor 100 outputs an erroneous proximity detection result due to a change in the characteristics of the ambient light.

  For example, when a call is made without placing a mobile phone on the ear as in the hands-free mode, it is determined that there is no proximity even during the call. In this state, for example, when moving from indoor to outdoor, or conversely from outdoor to indoor, the characteristics of the proximity sensor 100 may change due to changes in the surrounding temperature environment or changes in the light source. In such a situation, when returning to the normal call mode and performing an action of bringing the object OB closer such that the mobile phone is put on the ear, the object OB may not be normally detected even if the object OB is brought closer.

  Therefore, when the state of the external ambient light is detected and held and the state changes, the external light determination unit 134 sets the initial calibration flag to “0” and the offset value is not updated in the initial calibration. After setting to the state, the calibration is always finished. Thereby, the offset value is not always updated in the calibration, and the initial calibration is executed again.

  A method for detecting a change in the state of external ambient light is, for example, the following method. That is, infrared light incident from the outside can be detected by detecting a current generated in the light receiving unit 102 without driving the light emitting unit 101 and emitting no infrared light from the light emitting unit 101. Thereby, it is possible to detect the state of external ambient light. The external light determination unit 134 compares the state of the external environment light at the time of startup acquired by the above method with the state of the external environment light at the time of constant calibration. It may be determined that is detected.

  Alternatively, in the proximity illuminance sensor 400 (see Embodiment 2) having both the proximity sensor function and the illuminance sensor function for detecting the illuminance of ambient ambient light, the illuminance sensor function detects the illuminance of external visible light and infrared light, respectively. It is possible. The external light determination unit 134 compares the ratio of visible light and infrared light of external environmental light at the time of startup with the ratio of visible light and infrared light at the time of calibration, and there is a change of a predetermined value or more. In this case, it may be determined that a change in external ambient light has been detected.

  The external light determination unit 134 transmits a signal indicating that the change of the external environment light is not detected to the average offset value calculation unit 135 when the change of the external environment light is not detected.

  When the external light determination unit 134 detects a change in external environmental light, the external light determination unit 134 transmits a signal indicating that a change in external environmental light has been detected to the flag determination unit 121.

(Average offset value calculator 135)
The average offset value calculation unit 135 uses the offset value stored in the storage unit 104 (the offset value stored in the storage unit 104 after the initial calibration: the first offset value) as the current value (the light receiving unit after the initial calibration). The current value of the measured current generated from 102) and the offset value (first offset value) are updated to average values.

  Specifically, when the average offset value calculation unit 135 receives a signal indicating that a change in external ambient light has not been detected from the external light determination unit 134, the average offset value calculation unit 135 stores the signal in the storage unit 104 based on the offset value calculated by the averaging process. Update the stored offset value.

  That is, when the offset value can be updated in the continuous calibration, the offset value in the continuous calibration is updated by the average offset value calculation unit 135 in the average offset value calculation unit 135. The averaging process is executed by the following equation, for example.

y (n) = α · y (n−1) + (1−α) · x (n)
= Y (n-1) + (1- [alpha]). {X (n) -y (n-1)} Expression (1)
In equation (1), y (n) is a newly calculated constant calibration result, and y (n−1) is a calibration result before the calculation (an offset value stored in the storage unit 104 after the initial calibration). X (n) is a digital signal (measured current value acquired by the corrected measured value calculation unit 131) output from the proximity sensor AD conversion unit 103 after the initial calibration. A difference between x (n) and y (n−1) is output from the proximity sensor 100 to the outside as a proximity detection result. That is, a value obtained by subtracting the offset value before being updated by the averaging process from the measured current value acquired by the corrected measured value calculation unit 131 is output to the outside as the proximity detection result. In addition, α is an averaging coefficient. Increasing the value of α reduces the amount of change when updating the offset value by constant calibration. Conversely, decreasing the value of α reduces the offset value by constant calibration. It is possible to increase the amount of change at the time of update.

  Further, the average offset value calculation unit 135 uses the y (n) calculated by the average offset value calculation unit 135, which is a constant calibration result, as a new offset value in the constant calibration, and is stored in the storage unit 104. Update the value.

  After updating the offset value, the average offset value calculation unit 135 ends the constant calibration process, and transmits a signal indicating that the constant calibration has ended to the flag determination unit 121.

(Initial calibration process)
FIG. 3 is a flowchart showing an example of the flow of initial calibration processing of the proximity sensor 100. As shown in FIG. 3, first, the proximity sensor 100 is turned on, or the proximity sensor 100 is activated by an activation signal, an activation command, or the like. This corresponds to when the mobile phone is turned on or when a call is received.

  Next, initial setting of the proximity sensor 100 is performed (S101). When the proximity sensor 100 has a setting register or the like and the setting can be changed from the outside, this may be performed from a control unit or the like of the mobile phone. When the initial setting of the proximity sensor 100 is impossible or unnecessary, the process of S101 is unnecessary.

  Next, an initial calibration execution determination is performed from S102 to S104. First, the flag determination unit 121 determines whether or not the initial calibration flag is “0” (S102: offset value update determination step). When the initial calibration flag is “0” (YES in S102), the offset value calculation unit 122 causes the light emitting unit 101 to emit light by supplying current to the light emitting unit 101, and the initial measurement generated in the light receiving unit 102. A current value is acquired (S103: light emission step and light reception step), and it is determined whether or not the initial measurement current value is equal to or less than an initial threshold value (S104). When the initial measured current value is equal to or smaller than the initial threshold value (YES in S104), the offset value calculation unit 122 updates the offset value (S105: first execution step). Specifically, the offset value calculation unit 122 calculates a new offset value and updates the offset value stored in the storage unit 104. Thereafter, the offset value calculation unit 122 sets the initial calibration flag in the storage unit 104 to “1” (S106), ends the initial calibration (S107), and shifts to a constant calibration process (S108).

  In S102, when the initial calibration flag is “1” (NO in S102), the offset value calculation unit 122 ends the initial calibration (S107) and shifts to a constant calibration process (S108).

  In S104, when the initial measured current value is larger than the initial threshold value (NO in S104), the offset value calculation unit 122 ends the initial calibration (S107) and shifts to a constant calibration process (S108).

(Continuous calibration process)
FIG. 4 is a flowchart showing an example of the flow of the constant calibration process of the proximity sensor 100. Note that the initial calibration process of FIG. 3 and the constant calibration process of FIG. 4 are performed continuously.

  As shown in FIG. 4, first, the corrected measurement value calculation unit 131 obtains a measurement current value by supplying a current to the light emitting unit 101, and corrects it based on the measurement current value and the offset value stored in the storage unit 104. A measured value is calculated (S201). Next, the constant threshold value determination unit 132 determines whether the corrected measurement value is always equal to or less than the threshold value (S202). When the corrected measurement value is always equal to or less than the threshold value (YES in S202), the lower limit threshold value determination unit 133 determines whether the corrected measurement value is equal to or less than the lower limit threshold value (S203).

  When the corrected measurement value is larger than the lower limit threshold (NO in S203), the external light determination unit 134 determines whether or not the external environment light has changed (S204). If the external ambient light has not changed (NO in S204), the average offset value calculator 135 updates the offset value (S205: second execution step). Specifically, the offset value stored in the storage unit 104 is updated with the offset value calculated by the averaging process. After that, the average offset value calculation unit 135 always ends the calibration (S207), and proceeds to the initial calibration process (S208).

  In S202, when the corrected measurement value is always larger than the threshold value (NO in S202), the constant threshold value determination unit 132 ends the constant calibration (S207), and proceeds to the initial calibration process (S208).

  In S203, when the corrected measurement value is equal to or lower than the lower threshold (YES in S203), the lower threshold determination unit 133 sets the initial calibration flag in the storage unit 104 to “0” (S206), and always ends the calibration (S207). ), The process proceeds to the initial calibration process (S208).

  If the external ambient light changes in S204 (YES in S204), the external light determination unit 134 sets the initial calibration flag of the storage unit 104 to “0” (S206), ends the constant calibration (S207), The process proceeds to the initial calibration process (S208).

  Note that the determination order of S202 to S204 shown here is an example, and it is not necessary to make it the same as this embodiment, and even if the order is changed, the result of calibration is not affected.

[Embodiment 2]
The proximity illuminance sensor 400 according to the embodiment of the present invention will be described below with reference to FIG. For convenience of explanation, members having the same functions as those described in the first embodiment are denoted by the same reference numerals and description thereof is omitted. FIG. 5 is a functional block diagram showing a schematic configuration of the proximity illuminance sensor 400 according to Embodiment 2 of the present invention. The proximity illuminance sensor 400 includes the proximity sensor 100 having an illuminance sensor function for detecting the illuminance of external ambient light.

  A proximity illuminance sensor 400 shown in FIG. 5 has both a proximity sensor function for detecting whether or not a detection object is close and an illuminance sensor function for measuring the illuminance of external ambient light. 402, a proximity sensor AD conversion unit 403, a storage unit 404, an illuminance sensor AD conversion unit 405, and a proximity illuminance sensor control unit 410.

  The light emitting unit 401, the light receiving unit 402, the proximity sensor AD converting unit 403, and the storage unit 404 have substantially the same functions as the light emitting unit 101, the light receiving unit 102, the proximity sensor AD converting unit 103, and the storage unit 104 shown in FIG. Have.

  Further, each component of the proximity illuminance sensor control unit 410 (light emission instruction unit 411, measurement current value acquisition unit 412, initial calibration execution unit 420, flag determination unit 421, offset value calculation unit 422, constant calibration execution unit 430, correction The measurement value calculation unit 431, the constant threshold value determination unit 432, the lower limit threshold value determination unit 433, the external light determination unit 434, and the average offset value calculation unit 435) are components of the proximity sensor control unit 110 (light emission instruction unit 111, measurement current). Value acquisition unit 112, initial calibration execution unit 120, flag determination unit 121, offset value calculation unit 122, constant calibration execution unit 130, corrected measurement value calculation unit 131, constant threshold value determination unit 132, lower limit threshold value determination unit 133, outside It has the same function as the light determination unit 134 and the average offset value calculation unit 135).

  That is, the proximity illuminance sensor 400 shown in FIG. 5 is different from the proximity sensor 100 shown in FIG. 1 in that the illuminance sensor AD conversion unit 405 is further provided, and the other configurations are the same.

  The proximity illuminance sensor 400 detects the illuminance of external environmental light by the light receiving unit 402 receiving external light (external environmental light) and generating a current corresponding to the received light amount in the illuminance sensor AD conversion unit 405. be able to. An outline of the operation of the proximity illuminance sensor control unit 410 will be described below.

  During the proximity sensor operation, the proximity illuminance sensor control unit 410 emits infrared light from the light emitting unit 401 and the light receiving unit 402 receives the infrared light reflected by the object OB. The current generated in the light receiving unit 402 is input to the proximity sensor AD conversion unit 403. The proximity sensor AD conversion unit 403 is configured by an integration circuit, a comparator circuit, and the like. The proximity sensor AD conversion unit 403 accumulates electric charge flowing in by current, and can convert it into a digital signal by detecting the amount of electric charge. This digital signal is output from the proximity illuminance sensor 400 to the outside via the proximity illuminance sensor control unit 410.

  At this time, the output digital signal is processed by the initial calibration execution unit 420 and the constant calibration execution unit 430, corrected using the offset value stored in the storage unit 404, and output from the proximity illuminance sensor 400. .

  Here, the operation and method of calibration (initial calibration and constant calibration) are the same as those in FIGS. 3 and 4 and will not be described. Note that the illuminance sensor AD conversion unit 405 is turned off by the proximity illuminance sensor control unit 410 when the proximity illuminance sensor 400 operates.

  On the other hand, when the illuminance sensor is operated, the proximity illuminance sensor control unit 410 turns off the light emitting unit 401 and the proximity sensor AD conversion unit 403 and operates the illuminance sensor AD conversion unit 405.

  The light receiving unit 402 receives external ambient light and generates a current corresponding to the received light amount. The current is input to the illuminance sensor AD conversion unit 405 and converted into a digital signal in the same manner as the proximity sensor AD conversion unit 403. This digital signal is output from the proximity illuminance sensor 400 to the outside via the proximity illuminance sensor control unit 410.

  At this time, the output digital signal is processed by the initial calibration execution unit 420 and the constant calibration execution unit 430, corrected using the offset value stored in the storage unit 404, and output from the proximity illuminance sensor 400. .

  When the calibration of the present invention is performed using the proximity illuminance sensor 400, it is easy to detect a change in external ambient light in S204 in FIG. 4, and the calibration accuracy of the proximity illuminance sensor 400 can be improved. is there.

[Embodiment 3]
The third embodiment of the present invention will be described below with reference to FIGS. For convenience of explanation, members having the same functions as those described in the embodiment are given the same reference numerals, and descriptions thereof are omitted.

(Use of proximity sensor)
An example of the use of the proximity sensor 100 will be described. First, as an example, a case where a mobile phone and a media player are used as electronic devices will be described.

  When the mobile phone receives an incoming call, the user performs an operation of placing the mobile phone on the ear. At that time, if the display of the screen with the touch panel is ON and the touch panel function is in an active state, the mobile phone may malfunction if the human skin hits the screen by placing the mobile phone on the ear. In order to prevent such a malfunction, the proximity sensor 100 is used.

  Specifically, when the screen display is ON and the touch panel function is in an active state and an incoming call is received, the proximity sensor 100 is detected when the mobile phone is applied to the ear and the proximity sensor 100 detects proximity. Depending on the result, the control unit provided in the mobile phone performs the following control.

  That is, when there is an incoming call when the screen display is ON and the touch panel function is active, and the proximity sensor 100 detects human skin that is close, the control unit turns off the screen display and activates the touch panel function. Switch from to inactive. When the proximity sensor 100 detects that the human skin and the mobile phone have transitioned from the proximity state to the non-proximity state due to the end of the call and the separation of the mobile phone from the human skin, the control unit displays the screen. At the same time, the touch panel function is switched to active again.

  Next, an example in which the proximity sensor 100 is used in a media player that is a mobile device will be described.

  First, a media player not equipped with the proximity sensor 100 will be described. In a media player that does not include the proximity sensor 100, a user normally presses a button to turn off the power of a screen with a touch panel provided in the media player. The screen power is turned off, for example, when the media player is put in a pocket.

  On the other hand, the control unit provided in the media player equipped with the proximity sensor 100 performs the following control according to the detection result of the proximity sensor 100.

  That is, when a media player equipped with the proximity sensor 100 is placed in a pocket while the screen display is ON and the touch panel function is active, the media player and the cloth for the clothes (or the cloth for the pocket) come close to each other. Is detected by the proximity sensor 100. In this case, the control unit turns off the screen display and switches the touch panel function to inactive.

  Further, when the media player is taken out of the pocket and the media player and the cloth of the clothes (or the cloth of the pocket) are detected as not in proximity by the proximity sensor 100, the control unit turns the display on again. At the same time, the function of the touch panel is switched to active again.

  By performing the control as described above, it is possible to prevent a mobile device such as a media player from malfunctioning due to the touch panel function being active during a period not intended by the user. Moreover, it is possible to reduce power consumption by turning off the screen display.

  Next, a specific example of an electronic device including the proximity sensor 100 will be described with reference to FIGS. 6 and 7 show examples of the electronic apparatus according to the present embodiment, respectively. FIG. 6 is a perspective view illustrating an example of an electronic apparatus according to the present embodiment. The electronic device shown in FIG. FIG. 7 is a rear view showing another example of the electronic apparatus according to the present embodiment. The electronic device shown in FIG.

  As shown in FIG. 6, the mobile phone 500 includes any one of the proximity sensor 100 and the proximity illuminance sensor 400 described above as the proximity sensor 501 at the top of the display unit 502. The mobile phone 500 switches the display 502 on / off and the touch panel operation on / off according to the proximity / non-proximity of the object OB (see FIG. 2).

  By providing the proximity sensor 100 or the proximity illuminance sensor 400 as the proximity sensor 501, it is possible to improve the calibration accuracy compared to the conventional sensor, and as a result, it is possible to reduce malfunction of the mobile phone 500. It becomes. In particular, calibration is continued even when the characteristics of the proximity sensor 501 change due to changes in external temperature, external ambient light, etc. while the proximity sensor 501 continues to operate in a non-proximity state such as hands-free mode during a call. As a result, the output value of the proximity sensor 501 can be stabilized, and as a result, malfunctions of the mobile phone 500 can be reduced.

  As illustrated in FIG. 7, the digital camera 600 includes any one of the proximity sensor 100 and the proximity illuminance sensor 400 described above as the proximity sensor 601 at the top of the display unit 602. The digital camera 600 switches on / off the display of the display unit 602 according to the proximity state / non-proximity state of the object OB. For example, when the user of the digital camera 600 photographs a subject while confirming the display unit 602 and shoots with the digital camera 600, the control unit included in the digital camera 600 determines that it is in a non-proximity state and the display unit 602 is turned on. The On the other hand, when the user looks into the viewfinder of the digital camera 600 and photographs the subject, the control unit determines that the camera is in the proximity state and the display unit 602 is turned off.

  As a result, the power consumption of the digital camera 600 can be reduced. Further, in the case where the display unit 602 is provided with a touch panel function, it is possible to prevent a malfunction when the user's face touches the display unit 602 by turning off the touch panel function in the proximity state.

  By providing the proximity sensor 601 or the proximity illuminance sensor 400 as the proximity sensor 601, it becomes possible to improve the calibration accuracy as compared with the conventional sensor, and as a result, it is possible to reduce malfunction of the digital camera 600. Become. Even when the characteristics of the proximity sensor 601 change due to changes in external temperature, external ambient light, etc. in a state where the proximity sensor 601 continues to operate in a non-proximity state, such as when the user is not looking through the viewfinder, By continuing the calibration, it is possible to stabilize the output value of the proximity sensor 601 and to reduce malfunctions as a result.

[Example of software implementation]
The control block of the proximity sensor 100 may be realized by a logic circuit (hardware) formed in an integrated circuit (IC chip) or the like, or may be realized by software using a CPU (Central Processing Unit).

  In the latter case, the proximity sensor 100 includes a CPU that executes instructions of a program that is software that implements each function, a ROM (Read Only Memory) in which the program and various data are recorded so as to be readable by a computer (or CPU), or A storage device (these are referred to as “recording media”), a RAM (Random Access Memory) that expands the program, and the like are provided. And the objective of this invention is achieved when a computer (or CPU) reads the said program from the said recording medium and runs it. As the recording medium, a “non-temporary tangible medium” such as a tape, a disk, a card, a semiconductor memory, a programmable logic circuit, or the like can be used. The program may be supplied to the computer via an arbitrary transmission medium (such as a communication network or a broadcast wave) that can transmit the program. The present invention can also be realized in the form of a data signal embedded in a carrier wave in which the program is embodied by electronic transmission.

[Summary]
The proximity sensor (100) according to the first aspect of the present invention includes a light emitting unit (101) that emits light, and an object reflected photocurrent according to the amount of reflected light that is emitted from the light emitting unit and reflected by a detection target object. And a light receiving unit (102) that generates a measurement current including a non-detection target object reflected photocurrent according to a received light amount of light other than the reflected light, and a current value of the measurement current is equal to or less than an initial threshold value And updating the offset value according to the current value of the non-detection target object reflected photocurrent based on the current value of the measurement current, and not updating the offset value when the current value of the measurement current is larger than the initial threshold value. And a first execution unit (initial calibration execution unit 120) that executes one calibration.

  According to the above configuration, the offset value according to the detection target object reflected photocurrent generated by the light receiving unit according to the amount of received light other than the light reflected by the detection target object is when the measured current value is equal to or less than the initial threshold value. It is updated by the first calibration and is not updated when the measured current value is larger than the initial threshold value.

  Thereby, for example, when the initial threshold value is a value including a proximity detection threshold value used for determining that there is proximity and a current value that is considered to be generated by internal reflection, the measured current value generated in the light receiving unit is When it is larger than the initial threshold, it is considered that the measurement current is generated when there is an adjacent detection target object. Therefore, it is not suitable for use in updating the offset value. Therefore, when the measured current value is larger than the initial threshold value, an appropriate offset value can always be set by not updating the offset value in the first calibration. In other words, with the above configuration, calibration considering floor noise can be performed appropriately. As a result, proximity determination can be performed using an appropriate offset value, so that proximity can be accurately detected.

  The proximity sensor (100) according to aspect 2 of the present invention is the proximity sensor (100) according to aspect 1, wherein the first offset value, which is an offset value after the first calibration is performed, is received after the first calibration is performed. A second execution unit (always calibration execution unit 130) that executes a second calibration for updating the current value of the measurement current generated from the unit and the first offset value to an averaged value. preferable.

  According to the above configuration, the first offset value that is the offset value after the first calibration is updated by the second calibration to a value obtained by averaging the measured current value and the first offset value. For example, the offset value can be a value that gradually follows floor noise and external changes. Thereby, a highly accurate offset value can be set.

  The proximity sensor (100) according to Aspect 3 of the present invention is the proximity sensor (100) according to Aspect 2, wherein, in the second calibration, the first calibration is performed based on a current value of a measurement current generated from the light receiving unit after executing the first calibration. It is preferable that the first offset value is updated when the corrected measurement value obtained by subtracting the offset value is always equal to or less than the threshold value.

  According to the above configuration, for example, when the proximity detection threshold value used for determining that there is always proximity is used, the first offset value in the second calibration when there is a detection target object in proximity. It is not possible to update. Thereby, the second calibration can be appropriately executed.

  In the proximity sensor (100) according to aspect 4 of the present invention, in the aspect 2, the first calibration and the second calibration are executed alternately, and the second calibration performs the first calibration. It is preferable that the first offset value is not updated when a corrected measurement value obtained by subtracting the first offset value from the current value of the measurement current generated from the light receiving unit after execution is equal to or lower than a lower limit threshold value.

  According to the above configuration, for example, if the lower limit threshold is a value obtained by subtracting the offset value from the measured current value (initial measured current value) at the time of executing the first calibration, it can be determined that the first calibration is an erroneous calibration. In this case, the first calibration can be performed again without updating the first offset value in the second calibration. As a result, it is possible to eliminate the use of an offset value due to erroneous calibration as an output value, and therefore the accuracy of calibration is further increased.

  In the proximity sensor (100) according to the aspect 5 of the present invention, in the aspect 2, it is preferable that the first offset value is not updated when a change in external light is detected in the second calibration.

  According to the above configuration, when there is a change in external light, the first calibration can be performed again without updating the first offset value in the second calibration. As a result, the first calibration can be performed again in consideration of changes in external light.

  A proximity sensor (100) according to an aspect 6 of the present invention is the proximity sensor (100) according to any one of the aspects 5 described above, wherein an offset value update determination unit (flag determination unit 121) determines whether or not the offset value has been updated in the first calibration. The first execution unit updates the offset value in the first calibration when the offset value update determination unit determines that the offset value has not been updated in the first calibration. It is preferable to do.

  According to the above configuration, since the first calibration is performed when it is determined that the offset value is not updated in the first calibration, the first calibration and the second calibration are performed alternately. Can do.

  The proximity sensor (100) calibration method according to aspect 7 of the present invention includes: a light emitting step for emitting light; and an object reflected light corresponding to the amount of reflected light emitted in the light emitting step and reflected by the detection target object. A light receiving step for generating a measurement current including a current and a non-detection target object reflected photocurrent according to a received light amount of light other than the reflected light, and when the current value of the measurement current is equal to or less than an initial threshold value A first calibration that updates the offset value according to the current value of the non-detection target object reflected photocurrent based on the current value of the measurement current and does not update the offset value when the current value of the measurement current is larger than the initial threshold value. A first execution step for executing the operation.

  According to the said structure, there exists an effect similar to the aspect 1. FIG.

  The proximity sensor (100) calibration method according to aspect 8 of the present invention is the above-described aspect 7, in which the first calibration is performed using the first offset value, which is the offset value after the first calibration is performed. After that, it is preferable to include a second execution step of executing a second calibration for updating the current value of the measurement current generated in the light receiving step and the first offset value to an averaged value.

  According to the said structure, there exists an effect similar to the aspect 2. FIG.

  In the calibration method of the proximity sensor (100) according to the ninth aspect of the present invention, the current value of the measurement current generated from the light receiving step after executing the first calibration in the second calibration is the second calibration. It is preferable that the first offset value is updated when a corrected measurement value obtained by subtracting the first offset value from is always equal to or less than a threshold value.

  According to the said structure, there exists an effect similar to the aspect 3.

  The proximity sensor (100) calibration method according to aspect 10 of the present invention is the aspect 8 in which the first calibration and the second calibration are alternately performed, and in the second calibration, the first calibration is performed. When the corrected measurement value obtained by subtracting the first offset value from the current value of the measurement current generated from the light receiving step after performing one calibration is less than or equal to the lower threshold value, the first offset value is preferably not updated. .

  According to the said structure, there exists an effect similar to the aspect 4.

  In the calibration method of the proximity sensor (100) according to the aspect 11 of the present invention, the first offset value is not updated when a change in external light is detected in the second calibration in the aspect 8. Is preferred.

  According to the said structure, there exists an effect similar to the aspect 5. FIG.

  The proximity sensor (100) calibration method according to aspect 12 of the present invention is the offset value update determination for determining whether or not the offset value has been updated in the first calibration in any of the above aspects 7 to 11. And the first execution step updates the offset value in the first calibration when it is determined in the offset value update determination step that the offset value is not updated in the first calibration. It is preferable to do.

  According to the said structure, there exists an effect similar to the aspect 6. FIG.

  In the proximity illuminance sensor (400) according to Aspect 13 of the present invention, in the proximity sensor (100) according to any one of Aspects 1 to 6, the light receiving unit (402) receives external light and changes the received light amount. It is preferable to detect the illuminance of the external light by generating a corresponding current.

  According to the above configuration, it is possible to realize a proximity illuminance sensor that exhibits the same effect as that of the first aspect.

  An electronic device (mobile phone 500, digital camera 600) according to aspect 14 of the present invention includes the proximity sensor (100) according to any one of aspects 1 to 6, or the proximity illuminance sensor (400) according to aspect 13. It is preferable.

  According to the said structure, the electronic device which has an effect similar to the aspect 1 is realizable.

  The proximity sensor according to each aspect of the present invention may be realized by a computer. In this case, the proximity sensor is realized by the computer by operating the computer as each unit (software element) included in the proximity sensor. A proximity sensor control program and a computer-readable recording medium on which the control program is recorded also fall within the scope of the present invention.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention. Furthermore, a new technical feature can be formed by combining the technical means disclosed in each embodiment.

100 proximity sensor 101/401 light emitting unit 102/402 light receiving unit 120/420 initial calibration execution unit (first execution unit)
121 Flag determination unit (offset value update determination unit)
130/430 Constant calibration execution unit (second execution unit)
400 Proximity sensor 500 Mobile phone (electronic equipment)
600 Digital camera (electronic equipment)

The light receiving unit 102 includes a photodiode or the like, and generates a measurement current by detecting light. The measured current, and the object reflection light current corresponding to the received light amount of the reflected light L 2 reflected by the emitted object OB from the light emitting unit 101, the reflected light L 2 other than the light (e.g., reflected reflected by the housing 11 Non-detection target object reflected photocurrent according to the amount of received light L3). The measurement current generated by the light receiving unit 102 is output to the proximity sensor AD conversion unit 103.

In order to avoid this problem, the offset value after the initial calibration is set so that the value obtained by subtracting the offset value from the initial measurement current value (initial correction measurement value) exceeds the lower limit value (in this case, exceeds 0 ) . . Thereby, it is possible to determine after the initial calibration whether or not the executed initial calibration is an erroneous calibration.

The proximity sensor (100) according to Aspect 6 of the present invention is the proximity sensor (100) according to any one of Aspects 1 to 5, wherein the offset value update determination unit (flag determination) determines whether or not the offset value has been updated in the first calibration. 121), and the first execution unit determines that the offset value is determined in the first calibration when the offset value update determination unit determines that the offset value is not updated in the first calibration. Is preferably updated.

Claims (15)

A light emitting unit for emitting light;
An object reflected photocurrent corresponding to the amount of reflected light emitted from the light emitting unit and reflected by the detection target object; and a non-detection target object reflected photocurrent corresponding to the amount of received light other than the reflected light. A light receiving section for generating a measurement current;
When the current value of the measurement current is equal to or less than an initial threshold, the offset value corresponding to the current value of the non-detection target object reflected photocurrent is updated based on the current value of the measurement current, and the current value of the measurement current is A first execution unit that executes a first calibration that does not update the offset value when greater than an initial threshold;
A proximity sensor comprising:   A first offset value, which is an offset value after the first calibration is executed, is averaged between the current value of the measurement current generated from the light receiving unit and the first offset value after the first calibration is executed. The proximity sensor according to claim 1, further comprising a second execution unit that executes a second calibration for updating to a processed value.   In the second calibration, when the corrected measurement value obtained by subtracting the first offset value from the current value of the measurement current generated from the light receiving unit after executing the first calibration is always equal to or less than the threshold value, the first calibration is performed. The proximity sensor according to claim 2, wherein the offset value is updated. The first calibration and the second calibration are executed alternately,
In the second calibration, when the corrected measurement value obtained by subtracting the first offset value from the current value of the measurement current generated from the light receiving unit after executing the first calibration is equal to or lower than a lower limit threshold value, The proximity sensor according to claim 2, wherein one offset value is not updated.   The proximity sensor according to claim 2, wherein, in the second calibration, the first offset value is not updated when a change in external light is detected. An offset value update determination unit that determines whether or not the offset value has been updated in the first calibration;
The first execution unit updates the offset value in the first calibration when the offset value update determination unit determines that the offset value is not updated in the first calibration. The proximity sensor according to any one of claims 1 to 5. A light emitting step for emitting light;
An object reflected photocurrent according to the amount of reflected light emitted in the light emitting step and reflected by the detection target object; and a non-detection target object reflected photocurrent according to the amount of received light other than the reflected light. A light receiving step for generating a measurement current;
When the current value of the measurement current is equal to or less than an initial threshold, the offset value corresponding to the current value of the non-detection target object reflected photocurrent is updated based on the current value of the measurement current, and the current value of the measurement current is A first execution step of executing a first calibration that does not update the offset value when greater than an initial threshold;
A proximity sensor calibration method comprising:   The first offset value, which is an offset value after the first calibration is executed, is averaged between the current value of the measurement current generated in the light receiving step and the first offset value after the first calibration is executed. The proximity sensor calibration method according to claim 7, further comprising a second execution step of executing a second calibration for updating to a processed value.   In the second calibration, when the corrected measurement value obtained by subtracting the first offset value from the current value of the measurement current generated from the light receiving step after executing the first calibration is always equal to or less than a threshold value, the first calibration is performed. 9. The proximity sensor calibration method according to claim 8, wherein the offset value is updated. The first calibration and the second calibration are executed alternately,
In the second calibration, when the corrected measurement value obtained by subtracting the first offset value from the current value of the measurement current generated from the light receiving step after executing the first calibration is equal to or lower than a lower limit threshold, the second calibration is performed. 9. The proximity sensor calibration method according to claim 8, wherein one offset value is not updated.   9. The proximity sensor calibration method according to claim 8, wherein, in the second calibration, the first offset value is not updated when a change in external light is detected. An offset value update determination step for determining whether or not the offset value has been updated in the first calibration;
The first execution step updates the offset value in the first calibration when it is determined in the offset value update determination step that the offset value is not updated in the first calibration. The proximity sensor calibration method according to any one of claims 7 to 11. The proximity sensor according to any one of claims 1 to 6,
The proximity illuminance sensor, wherein the light receiving unit receives external light and detects an illuminance of the external light by generating a current corresponding to the received light quantity.   An electronic apparatus comprising the proximity sensor according to claim 1 or the proximity illuminance sensor according to claim 13.   A program for causing a computer to execute the proximity sensor calibration method according to any one of claims 7 to 12.

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